It can and does matter, which is why I'm asking, as it is important to the diagnostic process.
Chances are this is an internal issue in the tv, the wireless adapter card inside these tvs have very high failure rates.
There are some steps we can take to reset and reconfigure both the router and the tv, but ultimately further repairs may be required.
IF the router really is that close to the tv though, the wifi connection is not only unnecessary, but can even be counterproductive.
When in close proximity, you are actually better off using a WIRED ethernet connection, meaning to plug an lan/ethernet cable from the router to the tv. This gives the tv a direct connection which is not only faster, but also more stable, it wont' cut out or buffer like the wifi connection would.
I'm happy to go through the other steps with you, if you want to try, but for the cost of a $5 cord you can just plug in, you'd save yourself a lot of time and frustration by just switching to the wired connection, which should work automatically upon plugging it in. I would recommend making that switch.
If you don't have a cord handy, you can pick one up anywhere that sells computers or electronics, or online: http://amzn.to/1WXxdvL